Policy Brief: GRI, ESRS and TSRS
Differences, Overlaps, and a Strategy for Alignment

Three major sustainability reporting frameworks dominate the global landscape: the European Sustainability Reporting Standards (ESRS), now legally binding across the EU; the Global Reporting Initiative (GRI), the world’s most widely adopted voluntary standard; and the IFRS S1–S2 standards, focused on investor-oriented financial disclosures. Türkiye has joined this new era through the TSRS (Türkiye Sustainability Reporting Standards), a localized and mandatory version of the IFRS standards.

This policy brief aims to clarify the differences and overlaps between these three frameworks and outline an effective alignment strategy for companies operating in Türkiye.

General Characteristics of the Standards

Feature	GRI	ESRS	TSRS
Primary Source	GRI Standards (Netherlands)	CSRD & EFRAG (EU)	IFRS S1–S2 (ISSB)
Legal Status	Voluntary	Mandatory in the EU	Mandatory in Türkiye
Materiality Approach	Impact-based materiality	Double materiality (impact + financial)	Financial materiality only
Reporting Topics	ESG + stakeholder priorities	ESG + sector-specific requirements	ESG + financial risks and opportunities
Stakeholder Engagement	Narrative-driven, qualitative process	Structured analysis	Limited, investor-focused prioritization
Reporting Format	Flexible (PDF, web, etc.)	XBRL with technical annexes	XBRL-compatible, KGK template

Detailed Explanation of Differences

1. Materiality Principle

• GRI focuses on a company’s impacts on the environment, society, and workers.
• ESRS adopts a double materiality lens, incorporating both societal impacts and their financial consequences.
• TSRS considers only sustainability risks and opportunities that materially affect enterprise value—i.e., financial materiality only.

2. Mandatory Nature and Reporting Format

• GRI is voluntary and often led by corporate communications teams.
• ESRS is a legal obligation in the EU, with strict adherence to technical formats.
• TSRS, enforced by the Turkish Public Oversight Authority (KGK), applies to companies above a certain threshold and provides a risk-opportunity-centered framework aligned with IFRS.

3. Scope and Depth

• GRI allows rich storytelling but limited technical rigor.
• ESRS provides detailed topic- and sector-specific technical requirements.
• TSRS integrates such technical depth into financial disclosures but includes environmental and social externalities only when they result in financial impact.

Alignment Strategy: What Should Companies Do?

• 1. Map from GRI to TSRS: Existing GRI reports should be reviewed indicator by indicator. Impact-based narratives should only be retained under TSRS if they reflect material financial effects.
• 2. Integrate with the Finance Department: TSRS should be viewed as an extension of financial reporting. Sustainability, finance, and risk teams must collaborate closely.
• 3. Enhance Data Quality & Document Methods: TSRS uses a more technical and auditable language than GRI. All indicators must be accompanied by clear documentation of methodologies, scope, and data sources.
• 4. Prepare a Transition Plan: Companies should develop a 1–2 year roadmap for TSRS adoption. Start with a core set of indicators and gradually expand the scope.

Conclusion

TSRS introduces a new era of sustainability reporting in Türkiye. Its investor-oriented, financially material focus is a regulatory requirement, not a best practice option.

The right strategy is:
Maintain the narrative richness of GRI while achieving the investor-oriented clarity of TSRS.